Time synchronisation
To keep the server's clock accurate you need NTP. Network Time Protocol (NTP) is a network protocol for synchronising a computer's internal clock across networks with variable latency.
Modern systems: chrony
On AlmaLinux, Rocky Linux and CentOS 8 or later, synchronisation is handled
by chronyd:
dnf -y install chrony
systemctl enable --now chronydOn Ubuntu and Debian:
apt install chrony
systemctl enable --now chronyCheck synchronisation status:
chronyc tracking
timedatectl statusOlder systems: ntpd
Install the service:
yum -y install ntp # CentOS 6/7
apt-get install ntp # UbuntuSynchronise once, immediately:
ntpdate pool.ntp.orgStart the service:
systemctl start ntpd # CentOS 7
service ntpd start # CentOS 6
service ntp start # UbuntuEnable it at boot:
systemctl enable ntpd # CentOS 7
chkconfig ntpd on # CentOS 6
update-rc.d ntp defaults # UbuntuSee also configuring the time zone.